1. Field of the Invention
The present invention relates to a keyboard device.
2. Description of Related Art
A keyboard device of an electronic musical instrument such as an electronic piano includes a keyboard chassis and a plurality of keys (white keys and black keys). Generally, for example, an attachment portion to which the keys are attached is provided on a rear portion of the keyboard chassis, and rear end portions of the keys are fitted thereinto, whereby the keys are attached so as to be rotatable in an up-and-down direction.
However, in the case of attaching the keys by fitting the keys concerned as described above, there is an apprehension that the keys may be lifted or drop off at a time when a strong impact is applied to the keys from an outside.
Moreover, on a key tip end side of the keyboard device, key guide portions which guide the keys so that the keys can move only in the up-and-down direction are installed. If key guide portions made of a hard material are used, an abnormal sound occurs. Accordingly, the key guide portions are formed of a material with low hardness. Therefore, for example, in the case where the keys are pushed in a transverse direction or a diagonal direction, the keys have sometimes been inclined in the transverse direction or have sometimes wobbled therein.
Accordingly, heretofore, a device has been known, in which the keys are pivotally supported on the keyboard chassis so as to be freely swingable, and a pressing plate that inhibits lift-up of the rear end portions of the keys is thereafter arranged, whereby a configuration is adopted so as to prevent the lift-up or drop of the keys.
However, as described in Japanese Patent Laid-Open Publication No. H05-165460, in the case where the rear end portions of the keys are merely pressed by the pressing plate from above, smooth motion of the keys is inhibited when the rear end portions are pressed strongly. Meanwhile, it is insufficient if the rear end portions are merely pressed lightly for preventing the keys from being lifted up or dropping and the keys from being inclined and wobbling in the transverse direction when the strong impact is applied thereto.